ارزيابي تغييرات پوشش اراضي شهر ملاير با استفاده از سنجه‌هاي سيماي سرزمين

Land cover changes Assessment in Malayer using landscape metrics

زﻣﯿﻨﻪ و ﻫﺪف: ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ آﺛﺎر ﻣﻨﻔﯽ ﻧﺎﺷـﯽ از اﺳـﺘﻔﺎده ﻧﺎﻣﻨﺎﺳـﺐ از ﺳـﺮزﻣﯿﻦ و ﺗﻐﯿﯿـﺮ ﮐـﺎرﺑﺮي اراﺿـﯽ ، آﮔـﺎﻫﯽ و ﺷـﻨﺎﺧﺖ روﻧـﺪ ﺗﻐﯿﯿﺮﭘﺬﯾﺮي، در ارزﯾﺎﺑﯽ آﺛﺎر ﻣﺤﯿﻂ زﯾﺴﺘﯽ ﻧﺎﺷﯽ از ﺗﻮﺳﻌﻪ ﺑﻪ ﻣﻨﻈﻮر ﻃـﺮح رﯾـﺰي و ﻣـﺪﯾﺮﯾﺖ ﭘﺎﯾـﺪار ﺳـﺮزﻣﯿﻦ ﺿـﺮوري اﺳـﺖ. اﯾـﻦ ﻣﻄﺎﻟﻌﻪ ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ روﻧﺪ ﺗﻐﯿﯿﺮات ﺳﯿﻤﺎي ﺳﺮزﻣﯿﻦ در ﺷﻬﺮ ﻣﻼﯾـﺮ اﻧﺠـﺎم ﺷـﺪ. ﺷـﻬﺮ ﻣﻼﯾـﺮ ﺑـﻪ دﻟﯿـﻞ ﻋﻮاﻣـﻞ ﮔﻮﻧـﺎﮔﻮن ﻣﺎﻧﻨـﺪ اﻓﺰاﯾﺶ ﺟﻤﻌﯿﺖ، ﻧﻮﺳﺎزي ﻣﺤﻼت ﮔﺴﺘﺮش ﺣﻮﻣﻪ ﻧﺸـﯿﻨﯽ و... دﭼـﺎر ﺗﻐﯿﯿﺮاﺗـﯽ در ﭘﻮﺷـﺶ اراﺿـﯽ ﺷـﺪه اﺳـﺖ و ﻋﻮاﻣـﻞ واﺑﺴـﺘﻪ ﺑـﻪ ﺟﻤﻌﯿﺖ و ﺳﯿﺎﺳﺖ ﻫﺎي ﻣﺪﯾﺮان از ﺟﻤﻠﻪ ﻣﻮﺛﺮ ﺗﺮﯾﻦ آن ﻫﺎ ﻫﺴﺘﻨﺪ. روش ﺑﺮرﺳﯽ: ﺑﻪ ﻣﻨﻈﻮر ﺗﻬﯿﻪ ﻧﻘﺸﻪ ﻫﺎي ﭘﻮﺷـﺶ ﺳـﺮزﻣﯿﻦ و ﺗﺤﻠﯿـﻞ ﺗﻐﯿﯿـﺮات، از ﺗﺼـﺎوﯾﺮ ﻣـﺎﻫﻮاره اي ﻟﻨﺪﺳـﺖ در ﻓﺎﺻـﻠﻪ زﻣـﺎﻧﯽ ﺑﯿﻦ 2000 ﺗﺎ 2014 اﺳﺘﻔﺎده ﺷﺪو از ﺳﻨﺠﻪ ﻫﺎي ﻣﺴﺎﺣﺖ ﮐﻼس، ﺗﻌﺪاد ﻟﮑﻪ، ﺗـﺮاﮐﻢ ﻟﮑـﻪ، ﺑـﺰرگ ﺗـﺮﯾﻦ ﻟﮑـﻪ و ﺷـﮑﻞ ﻣﻨﻈﺮ اﺳـﺘﻔﺎده ﺷﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﺗﺠﺰﯾﻪ و ﺗﺤﻠﯿﻞ ﺳﻨﺠﻪ ﻫﺎي ﺳـﯿﻤﺎي ﺳـﺮزﻣﯿﻦ ﺑﯿـﺎن ﮔـﺮ ﺟـﺎﯾﮕﺰﯾﻨﯽ ﮔﺴـﺘﺮده زﻣـﯿﻦ ﺑـﺎز در ﻣﻨﻄﻘـﻪ ﺑـﺎ ﻣﻨـﺎﻃﻖ ﺳـﺒﺰ و ﺳﺎﺧﺘﻪ ﺷﺪه ﺑﻮده اﺳﺖ. ﺑﻪ ﮔﻮﻧﻪ اي ﮐﻪ ﺟﻤﻊ ﮐﻞ ﻣﺴـﺎﺣﺖ ﻓﻀـﺎﻫﺎي ﺳـﺒﺰ از ﺣـﺪود 396/8775 ﻫﮑﺘـﺎر در ﺳـﺎل 2000 ﺑـﻪ ﺣـﺪود 740/7900 ﻫﮑﺘﺎر در ﺳﺎل 2014 رﺳﯿﺪه اﺳﺖ و ﻣﯿﺰان اﻓﺰاﯾﺶ آن ﺣﺪود دو ﺑﺮاﺑﺮ ﺑـﻮده اﺳـﺖ. ﻫﻤﭽﻨـﯿﻦ ﻣﯿـﺰان اراﺿـﯽ ﺑـﺎز ﻧﯿـﺰ از ﺣﺪود 823/1400 ﻫﮑﺘﺎر در ﺳﺎل 2000 ﺑﻪ ﺣـﺪود 467/1400 ﻫﮑﺘـﺎر در ﺳـﺎل 2014 رﺳـﯿﺪه اﺳـﺖ و ﻧﺸـﺎن دﻫﻨـﺪه ﮐـﺎﻫﺶ 50 درﺻﺪي آن اﺳﺖ و اراﺿﯽ ﺳﺎﺧﺘﻪ ﺷﺪه ﻧﯿﺰ داراي اﻓﺰاﯾﺶ ﺣﺪود 12 ﻫﮑﺘﺎري ﻣﯽ ﺑﺎﺷـﻨﺪ. ﻣﯿـﺰان اﻓـﺰاﯾﺶ ﺗﻌـﺪاد ﻟﮑـﻪ ﻫـﺎ ﻧﯿـﺰ ﺑـﯿﺶ از دو ﺑﺮاﺑﺮ ﺑﻮده اﺳﺖ ﮐﻪ ﻧﺸﺎن از رﯾﺰداﻧﮕﯽ ﺳﯿﻤﺎي ﺳﺮزﻣﯿﻦ در ﻣﻨﻄﻘﻪ دارد.

Background and Objective: Due to the negative effects caused by the inappropriate use of land and land use changes, it is necessary to be aware about the variability process in the environmental impacts assessment witch arising from different developments to have the best planning and sustainable management of land. This study was conducted to check the effects of landscape changes in the city of Malayer. Malayer city due to various factors such as population growth, modernization of suburban neighborhoods and etc. is experiencing changes in land cover but among them the most effective factor is policies managers. Method: For achieving the studies objectives first step was mapping land cover change analysis, Landsat satellite images were used in the period between 2000 and 2014 and metrics were: class area (CA), number of patches (NP), patch density (PD), largest patch index (LPI) and landscape shape index (LSI). Findings: Findings like landscape metrics analysis shows wide replacement of open lands in the area with green and built lands. This means that from 2000 to 2014 green space is nearly doubled and open land also have decreased about 50%. Also the increase of number of patches was more than double that shows the microlithic landscape in the region. Discussion and Conclusion: The final results show that the changes of green lands are promising and improving and behind of this improvement there is nothing except management focus on green space which should continue in the future for sustainable development.